1. Technical Field
The present invention relates generally to pipe connectors, and, more specifically, to a branch connector for coupling a main pipe having a liner disposed therein with a service line and for simultaneously sealing the interface between the edges of the main pipe and the liner.
2. Background
A significant portion of the pipeline infrastructure in this country and abroad has become in need of reconstruction or rehabilitation. These pipelines distribute natural gas, water, and a variety of other fluids. One recently developed technology used for pipeline rehabilitation is known as CIPP (cured-in-place-pipe). This method of pipeline rehabilitation bonds a plastic lining to the inner wall of an existing pipeline using an adhesive mixture. The plastic lining serves as a primary barrier between the interior of the pipeline and the inner pipeline wall, which may have become subject to leakage due to age or stress. One of the advantages of the CIPP method of rehabilitation is that the complete pipeline length need not be excavated in order to be lined. This "trenchless" technology results in significant cost savings.
Every main pipeline has several smaller branch lines which transmit a fluid, such as gas or water, to end points, such as residences and businesses. Each of these service lines requires that a hole be drilled through the wall of the main pipe and through the liner to provide access to the fluid flow. At the locations where such holes are cut, there exists a mostly circular interface of pipe and liner edges which are exposed to the line pressure of the fluid delivery system. It is desirable to provide a seal at this cut-out interface to prevent the fluid from migrating along potential separations or voids created due to incomplete bonding between the pipe and the liner.
It is an object of this invention to provide a fitting for connecting a lined main pipe with a service line while simultaneously effectively sealing the main pipe and liner interface at the cut-out area.